Various types of devices have been experimentally and commercially used for recovering hydrocarbons from tar sands. Other devices are particularly intended for disposing of solid waste, such as rubber particles from used tires. One type of experimental device utilized a heated enclosure with an interior chamber and a conveyor for inputting tar sands to the heated enclosure. A condenser received vapors from the heated enclosure and output liquid hydrocarbons and gas hydrocarbons. Vacuum pumps have been used in some experimental units to maintain a selected vacuum within the heated enclosure, such that hydrocarbon vapors are drawn from the heated enclosure to the condenser. The prior art systems known to Applicants contain no effective way of monitoring the vacuum within the system at potential leak sites. Conventional packing was used on the end of auger tube shafts to maintain a vacuum.
Prior art systems for recovering hydrocarbons from tar sands include U.S. Pat. Nos. 4,624,417; 4,769,149; 4,857,458; 4,882,903; 5,429,645; 5,996,512; 6,938,562; and 6,848,375, as well as Patent Application Publications 2004/0103831 and 2004/0192980.
The disadvantages of the prior art are overcome by the present invention, and an improved system and method are hereinafter disclosed for recovering hydrocarbons from tar sands.